I beleive that these variables deal with the mapping of your specified
contrasts onto the reduced design matrix that is created to deal with
non-orthogonality of regressors in the original design matrix. Thus,
building your contrasts by directly writing the xCon variables this way
will cause problems. It's probably a better idea to build contrasts
using the batch system.
cheers
russ
On Wednesday, September 4, 2002, at 04:09 AM, Armin de Greiff wrote:
> Dear all,
>
> I want to manipulate the xCon of a fixed effects group analysis (two
> conditions per subject, block design convolved with hrf and temporal
> derivative).
> Starting with manually entered contrasts for the first subject I tried
> the
> following:
>
> % all contrasts for the first subject defined with contrast manager
>
> no_subjects = 8; % number of subjects
> no_conditions = 4; % number of conditions
> no_f_cons = 1; % number of f-contrasts
> no_cps = 4; % number of colums per subject
>
> for i=1:no_subjects-1
> for j=1:no_conditions
> act_con=i*no_conditions+j+no_f_cons;
> c_vek = zeros(size(xCon(2).c));
> c_vek(i*no_cps+1:(i+1)*no_cps) = xCon(j).c(1:no_cps);
> xCon(act_con) = xCon(j+no_f_cons);
> xCon(act_con).name = sprintf('%s %d',xCon(j+no_f_cons).name,i+1);
> xCon(act_con).c = c_vek;
> end
> end
>
> which works fine so far, but I don`t know what to do with xCon.X0 and
> X1o -
> any advice?
>
> Thanks in advance
>
> Armin de Greiff
>
----
Russell A. Poldrack, Ph.D.
UCLA Department of Psychology
Franz Hall, Box 951563
Los Angeles, CA 90095-1563
email: [log in to unmask]
phone: 310-794-1224
fax: 310-206-5895
web: http://www.poldracklab.org/
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